SQL Data Types

Question 1

CHAR(size)

Answer 1

A FIXED length string (can contain letters, numbers, and special characters). Thesizeparameter specifies the column length in characters - can be from 0 to 255. Default is 1

Question 2

VARCHAR(size)

Answer 2

A VARIABLE length string (can contain letters, numbers, and special characters). Thesizeparameter specifies the maximum string length in characters - can be from 0 to 65535

Question 3

BINARY(size)

Answer 3

Equal to CHAR(), but stores binary byte strings. Thesizeparameter specifies the column length in bytes. Default is 1

Question 4

VARBINARY(size)

Answer 4

Equal to VARCHAR(), but stores binary byte strings. Thesizeparameter specifies the maximum column length in bytes.

Question 5

TINYBLOB

Answer 5

For BLOBs (Binary Large Objects). Max length: 255 bytes

Question 6

TINYTEXT

Answer 6

Holds a string with a maximum length of 255 characters

Question 7

TEXT(size)

Answer 7

Holds a string with a maximum length of 65,535 bytes

Question 8

BLOB(size)

Answer 8

For BLOBs (Binary Large Objects). Holds up to 65,535 bytes of data

Question 9

MEDIUMTEXT

Answer 9

Holds a string with a maximum length of 16,777,215 characters

Question 10

MEDIUMBLOB

Answer 10

For BLOBs (Binary Large Objects). Holds up to 16,777,215 bytes of data

Question 11

LONGTEXT

Answer 11

Holds a string with a maximum length of 4,294,967,295 characters

Question 12

LONGBLOB

Answer 12

For BLOBs (Binary Large Objects). Holds up to 4,294,967,295 bytes of data

Question 13

ENUM(val1, val2, val3, …)

Answer 13

A string object that can have only one value, chosen from a list of possible values. You can list up to 65535 values in an ENUM list. If a value is inserted that is not in the list, a blank value will be inserted. The values are sorted in the order you enter them

Question 14

SET(val1, val2, val3, …)

Answer 14

A string object that can have 0 or more values, chosen from a list of possible values. You can list up to 64 values in a SET list

Question 15

BIT(size)

Answer 15

A bit-value type. The number of bits per value is specified insize. Thesizeparameter can hold a value from 1 to 64. The default value forsizeis 1.

Question 16

TINYINT(size)

Answer 16

A very small integer. Signed range is from -128 to 127. Unsigned range is from 0 to 255. Thesizeparameter specifies the maximum display width (which is 255)

Question 17

BOOL

Answer 17

Zero is considered as false, nonzero values are considered as true.

Question 18

BOOLEAN

Answer 18

Equal to BOOL

Question 19

SMALLINT(size)

Answer 19

A small integer. Signed range is from -32768 to 32767. Unsigned range is from 0 to 65535. Thesizeparameter specifies the maximum display width (which is 255)

Question 20

MEDIUMINT(size)

Answer 20

A medium integer. Signed range is from -8388608 to 8388607. Unsigned range is from 0 to 16777215. Thesizeparameter specifies the maximum display width (which is 255)

Question 21

INT(size)

Answer 21

A medium integer. Signed range is from -2147483648 to 2147483647. Unsigned range is from 0 to 4294967295. Thesizeparameter specifies the maximum display width (which is 255)

Question 22

INTEGER(size)

Answer 22

Equal to INT(size)

Question 23

BIGINT(size)

Answer 23

A large integer. Signed range is from -9223372036854775808 to 9223372036854775807. Unsigned range is from 0 to 18446744073709551615. Thesizeparameter specifies the maximum display width (which is 255)

Question 24

FLOAT(size,d)

Answer 24

A floating point number. The total number of digits is specified insize. The number of digits after the decimal point is specified in thedparameter. This syntax is deprecated in MySQL 8.0.17, and it will be removed in future MySQL versions

Question 25

FLOAT(p)

Answer 25

A floating point number. MySQL uses thepvalue to determine whether to use FLOAT or DOUBLE for the resulting data type. Ifpis from 0 to 24, the data type becomes FLOAT(). Ifpis from 25 to 53, the data type becomes DOUBLE()

Question 26

DOUBLE(size,d)

Answer 26

A normal-size floating point number. The total number of digits is specified insize. The number of digits after the decimal point is specified in thedparameter

Question 27

DECIMAL(size,d)

Answer 27

An exact fixed-point number. The total number of digits is specified insize. The number of digits after the decimal point is specified in thedparameter. The maximum number forsizeis 65. The maximum number fordis 30. The default value forsizeis 10. The default value fordis 0.

Question 28

DEC(size,d)

Answer 28

Equal to DECIMAL(size,d)

Question 29

DATE

Answer 29

A date. Format: YYYY-MM-DD. The supported range is from ‘1000-01-01’ to ‘9999-12-31’

Question 30

DATETIME(fsp)

Answer 30

A date and time combination. Format: YYYY-MM-DD hh:mm:ss. The supported range is from ‘1000-01-01 00:00:00’ to ‘9999-12-31 23:59:59’. Adding DEFAULT and ON UPDATE in the column definition to get automatic initialization and updating to the current date and time

Question 31

TIMESTAMP(fsp)

Answer 31

A timestamp. TIMESTAMP values are stored as the number of seconds since the Unix epoch (‘1970-01-01 00:00:00’ UTC). Format: YYYY-MM-DD hh:mm:ss. The supported range is from ‘1970-01-01 00:00:01’ UTC to ‘2038-01-09 03:14:07’ UTC. Automatic initialization and updating to the current date and time can be specified using DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP in the column definition

Question 32

TIME(fsp)

Answer 32

A time. Format: hh:mm:ss. The supported range is from ‘-838:59:59’ to ‘838:59:59’

Question 33

YEAR

Answer 33

A year in four-digit format. Values allowed in four-digit format: 1901 to 2155, and 0000.